Yesterday upgraded successfully from kubuntu 24.04 to 24.10. Then immediately krfb stopped working. I launch krfb and the dialog shows as usual with Enable Desktop Sharing enabled, but if I untick it, then tick it again, shows the message:
Error — Desktop Sharing
Failed to start the krfb server. Desktop sharing will not work. Try setting another port in the settings and restart krfb.
Changing the port number and changing from xcb to qt doesn’t make any difference.
Any help? Looks like it’s a bug since was working perfectly fine in 24.04.
krfb
QSocketNotifier: Can only be used with threads started with QThread
Wayland: Detected invalid configuration: preferredFrameBufferPlugin is not pipewire: "qt"
QObject::connect(FrameBuffer, RfbServerManager): invalid nullptr parameter
I’ve found out that KDE/Plasma is not yet compatible with Wayland, and some programs will not work:
$ krfb --help
QSocketNotifier: Can only be used with threads started with QThread
$ x11vnc -usepw -forever -display :0
Enter VNC password:
Verify password:
Write password to /home/kde/.vnc/passwd? [y]/n
Password written to: /home/kde/.vnc/passwd
21/11/2024 10:40:28 x11vnc version: 0.9.16 lastmod: 2019-01-05 pid: 18145
21/11/2024 10:40:28 Wayland display server detected.
21/11/2024 10:40:28 Wayland sessions are as of now only supported via -rawfb and the bundled deskshot utility. Exiting.
The way to fix it is to use another desktop:
Plasma (Wayland): no remote desktop apps are working at least the ones I tried
Plasma (X11): freezes when trying to enter to desktop in normal session
Xubuntu Session: works fine
I selected Xubuntu Session and made it default in sddm.
After being logged in locally, go to Applications > Settings Manager > Session and Startup > Application Autostart > + Add > in command put “x11vnc --usepw -forever -display :0” > OK.
The command also works running it from the terminal.
Then after each login remote desktop over VNC is already running.
In Kubuntu 22.04 Krfb was running perfectly fine but in 22.10 Ubuntu switched to Wayland. The problem is that some software is not yet compatible, and probably won’t be until 23.04 or even later.
So my advice is STAY ON UBUNTU 22.04 LTS until 26.04 LTS comes out to avoid weird issues. On Arch linux this does not happen.
Not sure what the KDE version is for Kubuntu 24.10. The krfb on KDE 6.2 has the option of the pw plugin to work under wayland, and there’s also krdp which provides remote desktop for the rdp protocol.
I used kubuntu a long time ago and it’s KDE was not up to date, at that time I always heard about new KDE features in the news, but it was late (in years) to show up . I’ve since switched to neon.
It’s probably better to switch kubuntu to 24.04 LTS and use X11. or change to KDE Neon, which has fresh KDE versions.
PS: Krdp (not xrdp) is a new remote desktop feature in KDE, which may not be supported by the official Ubuntu repositories yet.
As an attempt, perhaps you could try checking if pipewire is installed, pw should depend on this component.
But even if pw works, the experience won’t be great, due to the fact that you have to request permissions locally for each connection.
What I don’t understand is why they updated software to non stable versions. Maybe that should have skipped the 24.10 release altogether and wait for proper stable versions.
. I’ve since switched to neon.